Summary: For biological products that are required to be sterile, testing mandated by the Code of Federal Regulations requires a 14 day incubation period, with observations based on visual examination of product-inoculated media, to conclude with reasonable confidence that the product is free from extraneous bacterial or fungal contamination. A group of newly emerging "rapid" methods suggests that such bacterial contamination can be detected in less than 14 days by other methods. The Microstar system, made by Millipore Corporation, utilizing bioluminescence to detect viable contaminating organisms, was selected for evaluation based on the laboratory's current use of existing Millipore Steritest equipment and supplies. Studies this year involved contamination introduced by injecting less than 50 CFU of selected organisms into a 200 ml vial of a target biological product; the product was then subjected to traditional sterility testing and a hybrid sterility test where small quantities of the inoculated media was assayed daily using the MicroStar methodology. The contamination was detected 48-72 hours earlier with the MicroStar procedure as compared to traditional sterility test. Work is continuing to increase the sensitivity of the MicroStar methodology, in terms correlation between contamination levels, types of organisms and detection time. Attempts were made this year to begin evaluating the MicroStar system for the detection of contaminants in cell based products. These products, that must be infused into patients prior to the completion of the 14 day incubation period, could be favorably impacted by the validation of the MicroStar System. Sham preparations of several cell types were contaminated with low numbers of bacterial CFU's; however, methods and reagents to specifically quench the bioluminescence of the mammalian or animal cells require further research.